MyPaint is a fast and easy open-source graphics application for digital painters. It lets you focus on the art instead of the program. You work on your canvas with minimum distractions, bringing up the interface only when you need it. MyPaint comes with a large brush collection including charcoal and ink to emulate real media, but the highly configurable brush engine allows you to experiment with your own brushes and with not-quite-natural painting.
You can install mypaint from Ubuntu software center of from by using the following command
sudo apt-get install mypaint
For Fedora 14 :
Download the file bellow
– For other Linux Distributions, download the tar file from this link